APA 7 Numerical Values
- Decimal
values: APA 7 requires a leading zero before the decimal for values less
than one when the statistic can be greater than one (e.g., p =
0.01), and omits the leading zero when it cannot exceed one (e.g., r =
.45). You’ve mostly followed this, but there are a few small
inconsistencies (e.g.,
- in
p-values, “p < .01” is correct,
- reliability
coefficients you should keep the leading zero: α = 0.87).
- Ensure
spaces are placed before and after equals signs in statistical reporting
(e.g., PNImodified = 0.53).
- Percentages
are correctly expressed with the % sign and a numeral (APA 7 allows this).
in APA Style (7th edition), fit indices such as RMR, RMSEA, CFI, TLI,
SRMR, and similar goodness-of-fit statistics are not italicized.
Here’s the general APA convention:
- Symbols
for test statistics (e.g., t, F, p, r, d, M, SD)
→ italicized because they are statistical symbols.
- Named
indices or acronyms (e.g., RMSEA, CFI, GFI, AIC) → written in regular
font, capitalized, no italics.
- Greek
letters (e.g., χ²)
→ italicized because they are mathematical/statistical symbols, not
acronyms.
So, in your excerpt:
- χ² → italicized because
it’s a statistical symbol.
- RMSEA
and CFI → regular (non-italic) font.
χ²(46) = 32.19, p = .94, RMSEA = 0.00, CFI = 1.00
(APA
prefers p-values in the form p = .94 rather than p = 0.94.)
in APA Style, table headings are not italicized.
Here’s how it breaks down for your example:
- Column
and row headers (e.g., Groups, Factors/Variables, Position,
Total, Teachers, Supervisors) → regular font,
no italics, but APA recommends sentence case (only the first word
and proper nouns capitalized).
- Statistical
symbols inside the table (e.g., β, t, R²) → italicized
because they are symbols.
- Factor
names (e.g., Solutions (SOL): Ability to solve problems) →
regular font, unless you’re referencing a scale title, in which case APA
says to italicize scale titles (not the variables themselves).
So your table headings would look like this in APA style:
|
Groups
|
Factors/variables
|
Position
|
Total
|
|
Teachers
|
|
|
|
β t R²
|
|
|
|
Supervisors
|
|
|
|
β t R²
|
|
|
It sounds like you’re asking about the coefficient of
determination, R2R^2R2, and whether it can be zero — possibly in the context
where R2≥0.75R^2 \geq 0.75R2≥0.75 is also mentioned.
Here’s the breakdown:
- What
R2R^2R2 is:
R2R^2R2 measures how well a model explains the variance in the dependent
variable.
- R2=1R^2
= 1R2=1 → perfect fit.
- R2=0R^2
= 0R2=0 → model explains none of the variance (predictions are no
better than simply using the mean).
- R2<0R^2
< 0R2<0 can occur if the model fits worse than a horizontal line at
the mean.
- Can
R2R^2R2 be zero?
Yes — R2=0R^2 = 0R2=0 is possible. It means the model’s predictions are
completely uncorrelated with the observed data.
But if you state R2≥0.75 R^2 \geq 0.75R2≥0.75, then you are
imposing a constraint: in that case, R2R^2R2 cannot be zero because 0 is
less than 0.75.
So:
- Without
constraint: Yes, R2R^2R2 can be zero.
- With
R2≥0.75 R^2 \geq 0.75R2≥0.75 requirement: No, zero is excluded by
definition.
ChatGPT said:
In APA 7th edition, the correct way to report R2R^2R2
(and similar statistics) depends on the context, but there are some consistent
rules.
1. Basic format for reporting R2R^2R2
- Use italic
for the symbol: R2R^2R2
- Include
two decimal places (unless your field requires more)
- If
reporting adjusted R2R^2R2, write it as adjusted R2R^2R2.
Example:
The model explained a significant proportion of variance in
scores, R2=.76,F(3,96)=12.45,p<.001R^2 = .76, F(3, 96) = 12.45, p <
.001R2=.76,F(3,96)=12.45,p<.001.
2. When R2R^2R2 is a main result
- State
clearly what the variance represents (what is predicted).
- Include
the FFF-test and degrees of freedom if from regression.
- Mention
adjusted R2R^2R2 if used.
Example:
A linear regression was conducted to predict exam scores
from study time, motivation, and sleep hours. The model was significant,
F(3,96)=12.45,p<.001F(3, 96) = 12.45, p < .001F(3,96)=12.45,p<.001,
and explained 76% of the variance in exam scores, R2=.76R^2 = .76R2=.76.
3. APA 7 notes for style
- Leading
zero: Omit before the decimal for values < 1 (write .76, not 0.76).
- p-values:
Write as p=.032p = .032p=.032 or p<.001p < .001p<.001.
- Rounding:
Usually 2 decimal places, but keep more if rounding would change the
interpretation (e.g., .004 vs .00).
4. Example with adjusted R2R^2R2
The model accounted for a significant proportion of the
variance in anxiety scores, R2=.32R^2 = .32R2=.32, adjusted
R2=.29,F(5,114)=10.42,p<.001R^2 = .29, F(5, 114) = 10.42, p <
.001R2=.29,F(5,114)=10.42,p<.001.
In APA 7th edition, you’d write the standard
deviation like this:
- Symbol
in italics: SD
- Numerical
value rounded appropriately (usually two decimal places)
- Leading
zero included before the decimal for values < 1
Example:
SD = 0.57
In-text example:
The participants’ mean anxiety score was 4.21 (SD =
0.57).
If you like, I can also show you the APA 7 full sentence
format for reporting M and SD together.
